Coffee consumption and glucose tolerance status in middle-aged Japanese men

Abstract

Aims/hypothesis. Several studies have reported that coffee has a protective effect against the development of type 2 diabetes. However, few of these studies used the standard glucose tolerance test to diagnose type 2 diabetes. The aim of this study was to investigate the relationship between coffee and green tea consumption and glucose tolerance status as determined using a 75-g OGTT. Methods. We performed a cross-sectional study of 3224 male officials of the self-defence forces. Glucose tolerance status was determined in accordance with the 1998 World Health Organization criteria, and average intakes of coffee and green tea over the previous year were assessed by a self-administered questionnaire. The figures obtained were adjusted for BMI, physical activity and other factors. Results.A total of 1130 men were identified as having glucose intolerance (IFG, IGT or type 2 diabetes). Compared with those who did not consume coffee on a daily basis, fasting and 2-h post-load plasma glucose levels were 1.5% and 4.3% lower in those who drank 5 cups of coffee or more per day respectively. The adjusted odds ratios of glucose intolerance for categories of <1, 1-2, 3-4 and ≥5 cups of coffee per day were 1.0 (referent), 0.8 (95% CI 0.6-1.0), 0.7 (95% CI 0.6-0.9) and 0.7 (95% CI 0.5-0.9) respectively (p=0.0001 for trend). No clear association was observed between green tea drinking and glucose tolerance status. Conclusions/interpretation. Coffee consumption may inhibit postprandial hyperglycaemia and thereby protect against the development of type 2 diabetes mellitus.

Coffee consumption and risk of total and cardiovascular mortality among patients with type 2 diabetes

“…So preventing hyperglycaemia means protecting cells from further progression of diabetes and its complications. Previous studies from diverse countries have revealed that higher coffee consumption was consistently associated with a lower prevalence of hyperglycaemia, and, in particular, coffee consumption seems to lower postprandial hyperglycaemia [47,48]. In our most recent study before this one, we also found lower fasting insulin values and lower risk of hyperinsulinaemia among coffee consumers with long-term exposure [49], which may be interpreted to mean that coffee consumption possibly improves insulin sensitivity, thereby preventing hyperglycaemia and oxidative stress.…”

Coffee consumption, serum γ-glutamyltransferase and risk of type II diabetes

“…In addition, coffee may also influence the secretion of gastrointestinal peptides such as glucagon-like peptide-1 and gastric inhibitory polypeptide; both of them are known for their glucose-lowering effects (Nauck et al, 1993;Meier et al, 2001). Recently, published results in diverse countries revealed that higher coffee consumption was consistently associated with a lower prevalence of hyperglycemia and in particular, coffee consumption seems to lower post-prandial hyperglycemia (Agardh et al, 2004;Van Dam et al, 2004;Yamaji et al, 2004;Bidel et al, 2006). Although acute administration of caffeine may reduce insulin sensitivity (Keijzers et al, 2002), we have found nonetheless lower fasting insulin values and a lower prevalence of hyperinsulinemia among coffee consumers with long-term exposure.…”

Tea Consumption and Risk of Type 2 Diabetes: A Meta-Analysis of Cohort Studies

“…Seven studies were excluded because they were other design types. 24,25,[35][36][37][38][39] A study by Mackenzie et al 40 was excluded because some participants had diabetes at baseline. Two articles were excluded because they did not provide 95% CI or data to calculate (Fig.…”